[技术]Arizona眼睛模型 [复制链接]

简介 '0<d9OlJ}  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 Pf*6/7S:  
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模型 ]P4WfV d  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 2w?q7N%  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ]g_VPx"  
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光源 %()d$.F  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 t*{L[c9.Uq  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 qt"D!S
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ?w3RqF@}  
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视网膜的散射 @CprC]X  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 *t@A-Sn  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 m%'nk"p9  
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脚本 KX)n+{   
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示：
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 X! d-"[  
余下的脚本计算与屈光度有关的所有参数。 (gt\R}  
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分析 _v!7 |&
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 .OPknC  
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脚本代码 &@~K8*tmK  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0~|0D#klB  
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Dim entity As T_ENTITY c&['T+X  
Dim op As T_OPERATION v%tjZ5x  
Dim mat As T_MODELMATERIAL Y
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Dim A As Double l6M?[  
Dim pupilDiam As Double u
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Dim eID As Long u 3WU0Z`  
Dim parID As Long ^<;W+dWdU  
Dim count As Integer _@5Xmr  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5Xq+lLW>  
Dim tlens As Double, nlens As Double ~ua(Qm  
Dim curv As Double, conic As Double }$ y.qqG  
Dim ok As Long |J$A%27  
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Sub Main u[a-9^&g  
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    '用户输入对话框 x]^d'o:cDP  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 FFT)m^4p.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lrrTeE*  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,NO[Piok  
        OKButton 40,91,90,21 YPK@BmAdE  
        CancelButton 190,91,90,21 5'!fi]Z  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z)R
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        TextBox 220,49,40,21,.TextBox2 'default: 4 Kz'GAm\  
    End Dialog ak7%  
    Dim dlg As UserDialog K1 f1T  
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    ok = Dialog (dlg) kQ\GVI11?  
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    If ok=0 Then    'cancel button was pressed NlYuT+  
        Print "Execution cancelled." |
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        End 7%h;To-<6  
    End If b9g2mWL\T  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1P)K@j  
    If dlg.TextBox1 = "" Then 4LSsWO<@  
        A = 0           'Default accommodation M$x,B#b  
    Else (Mv~0ShakO  
        A = CDbl(dlg.TextBox1) Dj/Hz\  
    End If L15)+^4n  
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    If dlg.TextBox2 = "" Then 1^_W[+<S/  
        pupilDiam = 4   'Default pupil diameter F:zmO5L5  
    Else 7mt
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        pupilDiam = CDbl(dlg.TextBox2) enk`I$Xx  
    End If O>E}Lu;|  
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    Print " " |s/)lA:9  
    Print "Accommodation = " & A & " Diopters" FQek+[ox  
    Print "Pupil Diameter = " & pupilDiam & " mm" g0
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    ' Calculate new parameters with accommodation h-p}Qil,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness XT/t\\Z`U  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @tT`s^e  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens  II'.vp  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <*vR_?!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  c@A.jc  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @@ j\OR  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c{^1`(#?  
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    'Adjust parameters to account for accommodation :@(1~Hm  
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    '************************************************************************* a3n Wt  
    'Aqueous thickness (Position of Lens) p$"~vA .  
    '************************************************************************* 5$i(f8*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ",apO  
    GetCustomElement eID, entity Pk&=\i<  
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    parID = FindFullName( "Geometry.Arizona Eye" ) "s@Hg1  
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    ' Delete any shift(s) in z LYAG
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    count = 0 }:?*n:g5  
    While GetOperationCount(eID)>count 9q]f]S.L  
        GetOperation eID, count, op Zzlt^#KLx  
        If op.Type="ShiftZ" Then PU%Zay  
            DeleteOperation eID,count P%B|HnG^  
            count=count-1 <\nM5-wR  
        End If 42e[OG-  
        count=count+1 ^/%o I;O{  
    Wend ]prw=rD  
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    'Set new shift in e'
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    op.Type = "ShiftZ" H/t0#  
    op.val1 = taq H-t$A, [  
    op.parent = parID YdV.+v(30  
    AddOperation eID, op 75>%!
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    Print "Set aqueous humor thickness = " & taq-0.55 XN-1`5:4I  
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    '************************************************************************* )4o8SF7lz  
    'Radius and conic constant of anterior lens [#wt3<d`)  
    '************************************************************************* S%H"i y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xqdkc^b  
    GetConic eID, entity, curv, conic A46dtFD{  
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    SetConic eID, entity, 1/Rant, CCant Qraq{'3  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #++:`Z  
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    '************************************************************************* =2*2$  
    'Radius and conic constant of posterior lens F
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    '************************************************************************* }2Ge??!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -7oIphJ=\  
    GetConic eID, entity, curv, conic },<Y \  
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    SetConic eID, entity, 1/Rpost, CCpost S^q^=q0F  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost uJ|,-"~F  
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    '************************************************************************* EId>%0s5  
    'Lens thickness (Position of posterior lens surface) HI1|~hOb'  
    '************************************************************************* p%Q{Rq
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ">B&dNrt  
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    ' Delete any z-shift(s) zn'Mi:O'p  
    count = 0 Lcg1X3$G  
    While GetOperationCount(eID)>count .: wg@Z  
        GetOperation eID, count, op AN,3[Sh  
        If op.Type="ShiftZ" Then !9qw  
            DeleteOperation eID,count 1C=42ZZ&2  
            count=count-1 F:Vl\YZ  
        End If )#Ecm<.^  
        count=count+1 -0'<7FSQ  
    Wend >y}> 5kv  
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    'Set new z-shift ?y%Mm09  
    op.Type = "ShiftZ" <%4pvn8d?&  
    op.val1 = tlens $v8T%'p+  
    op.parent = parID @CPkP  
    AddOperation eID, op
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    Print "Set lens thickness = " & tlens }WR@%)7ay  
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    '************************************************************************* _4{3^QZq5  
    'Lens index of refraction nbw8YO(=  
    '************************************************************************* EnMc9FN(y  
    eID = FindMaterial( "Lens" ) Vs>e"czfm/  
    GetModelMaterial eID, mat J,h'eY5  
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    mat.Nd = nlens E)'T
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    SetModelMaterial eID, mat .F/l$4CQ  
    Print "Set lens index of refraction = " & nlens .lg
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    '************************************************************************* ) [)1  
    'Pupil diameter D.F1^9Q  
    '************************************************************************* j<?k$8H  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) W9GjUswv!  
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    'Adjust pupil diameter (trimming volume inner hole) 25vq#sS]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =m;cy0))  
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    ' Adjust pupil location to just in front of the lens 7*+tG7I @  
    parID = FindFullName( "Geometry.Arizona Eye" ) x` 4|^u  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) | m#"  
    count = 0 meD83,L~N  
    While GetOperationCount(eID)>count h?QGJ^#8  
        GetOperation eID, count, op Vvn~G.&)  
        If op.Type="ShiftZ" Then "NV~lJS%  
            DeleteOperation eID,count SphP@J<ONW  
            count=count-1 e9F+R@8  
        End If -9
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        count=count+1 [L2N[vy;  
    Wend !'bZ|j%  
    op.Type = "ShiftZ" AB.ZmR9|  
    op.val1 = taq-0.01  o^d  
    op.parent = parID 7%|HtBXv^  
    AddOperation eID, op $3Sm?  
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    Print "Set pupil diameter = " & pupilDiam aqP"Y9l  
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    'Update AZ Eye subassembly Description ()_^:WQO?  
    eID = FindFullName( "Geometry.Arizona Eye" ) <@c9S,@t  
    GetEntity eID, entity tY`%vI [  
    entity.Description = "Accommodation = " & A & "D" o3:h!(#G  
    SetEntity eID, entity G'iE`4`2  
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    Update w!l*!G  
    Print "DONE!" 7] >z e  
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End Sub p+F>+OQ*  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： kI~;'M  
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Accommodation = 4 Diopters )%I62<N,z  
Pupil Diameter = 4 mm l=>FoJf!*<  
Set aqueous humor thickness = 2.81 WQNFHRfO*n  
Set anterior lens radius = 10.4 and conic constant = -2.375869 0w".o!2\U{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 U5;Y o+z  
Set lens thickness = 3.927 :w9s bW  
Set lens index of refraction = 1.42672 YZc{\~d  
Set pupil diameter = 4 ~#:R1~rh\e  
DONE! E(an
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